Pyrazoline bearing benzimidazoles: search for anticancer agent.

Abstract 2-acetyl benzimidazole was allowed to react with substituted aromatic aldehydes to get desired intermediate chalcones ( 2a – g ), the cyclocondensation of these intermediates with hydrazine hydrate and phenyl hydrazine in two separate reactions yielded pyrazoline derivatives ( 3a – g & 4a – g respectively). Among the synthesize compounds, six compounds were granted NSC code and screened at National Cancer Institute (NCI), USA for anticancer activity at a single high dose (10 −5 M ) in full NCI 60 cell panel. Among the selected compounds, ( 4f ) 2-[5-(3,4-dimethoxyphenyl)-1-phenyl-4,5-dihydro-1 H -3-pyrazolyl]-1 H -benzimidazole (NSC 748326) was found to be the most active candidate of the series and selected for further evaluation at five dose level screening.